Electronic Keyboards & synthesizers

The Electric Keyboard and the Synthesizer


The piano, in various forms, has been a mainstay of Western music for hundreds of years. While the traditional piano found its place in classical music at the hands of countless composers, its versatility has made it a favorite instrument in all types of popular music as well. In many cases, musicians have been thoroughly satisfied with the traditional piano, while others have experimented and found expression in the piano’s descendants, the electric keyboard and the synthesizer.

Where Did The Piano Come From?

The origins of the piano are somewhat vague. Distant ancestors of the piano were played even in ancient times, and there are references to possible piano forerunners that date as far back as the year 1157. However, the earliest conclusive information known concerning piano-like instruments refers to the clavichord.

The clavichord seems to have been invented some time around the beginning of the 15th century. The distinguishing feature of the clavichord is that it had a keyboard with keys that would cause strings inside the instrument to sound. The keyboard itself was an ancient idea already, having been used for organs and similar instruments as far back as the third century BCE. The idea of strings being struck, or plucked, in response to a keystroke also seems to have been in the air for some time before the clavichord appeared, but the clavichord seems to be the first instrument in which the two ideas were combined. The mechanism for causing the strings to sound is straightforward: each key is attached to a kind of metal hammer, known as a tangent. When the pianist strikes a key, the tangent swings up and strikes the string. There are two important features of the clavichord’s sounding mechanism that affected the development of the piano. First, the force of the tangent striking the string, and therefore the volume of the note, depends on how hard the pianist strikes the key. Second, the tangent stays in contact with the string as long as the pianist holds the key, which tends to dampen the note. Differences in the sounding mechanism are the primary difference between this piano forerunner and another important piano ancestor, the harpsichord.

The exact time of the invention of the harpsichord is as vague as that of the clavichord. The harpsichord appears, like the clavichord, to have been invented near the beginning of the 15th century, and it may be that at the time there was no clear distinction between the two types of instruments. There were, of course, no factories devoted to harpsichord or clavichord manufacture, no piano stores with a broad selection of keyboard instruments. Instrument makers crafted everything by hand, and gave names of their own choosing to the instruments. However, before long, the instrument that we recognize as the harpsichord began to appear. Overall it is very similar to the clavichord, with the significant difference being the mechanism for causing the strings to sound. In the harpsichord, each key on the keyboard is attached to a plectrum, which is a fancy Latin word for pick, in the sense of a guitar pick. Of course, the picks in those days weren’t made of plastic, or even tortoise shell. They were made of crow or owl quills, or sometimes leather. When the pianist strikes a key, the plectrum swings up and plucks the string, much as a guitarist would pluck a guitar string. An important result of this mechanism is that the intensity of the note, that is, the volume, does not respond very well to the force that the pianist uses in striking the key. The intensity of the note is about the same whether the pianist barely touches the key or hits it with all his might. A distinct advantage that this mechanism has over that of the clavichord is that the plectrum does not stay in contact with the string, so the note is not dampened. Instead, the string vibrates freely until it settles back into silence naturally.

The harpsichord, although it took some time to catch on, became especially popular among Baroque composers during the 17th century. Eventually, like all musicians, pianists seemed to begin wishing for something more. In particular, they must have wanted to enhance their expression by controlling the volume of the instrument, something that could not be done with the harpsichord. Enter the pianoforte.

The Piano Before Electricity

Credit is generally given to Bartolomeo Cristofori of Italy for creating the first modern piano, some time in the first decade of the 18th century. Cristofori called it “gravicembali col piano e forte”, a harpsichord with soft and loud, which was shortened to pianoforte, and eventually just piano. The significance of the name lay in soft and loud. An easy touch produces a very soft sound, while a forceful strike produces a very loud sound, as one intuitively expects from a typical modern piano. In Cristofori’s time, this was a major breakthrough. Using an incredibly complex mechanism attached to each key, Cristofori was able to combine a desired feature of the clavichord (a note whose intensity can be varied by the pianist) with a desired feature of the harpsichord (strings being left to vibrate instead of being dampened). Perhaps not surprisingly, this amazing new instrument was largely ignored until it received some good press, in the form of a glowing review in 1711 by Scipione Maffei. Aspiring artists take note.

Over the next couple of centuries, the piano grew and changed to keep up with the demands of composers and pianists. In Mozart’s day, a typical pianoforte spanned five octaves, while a modern piano spans more than seven. The industrial revolution introduced new technologies for creating better steel strings, and eventually the iron frames that were necessary to prevent the instrument from distorting under the tension of those numerous, high-quality strings. While Chopin was taking professional music lessons from Wojciech Żywny, a new kind of key mechanism, known as the double-escapement action, was invented. The primary advantage of this new mechanism was that it enabled the pianist to play the same key very rapidly in succession. One might listen to some of Chopin’s compositions and wonder how much he owed to this invention.

Sequencing Before Electricity

At the Centennial Exposition of 1876 in Philadelphia, several inventors exhibited pianos that played themselves automatically. These were the forerunners of the player piano. The player piano could “read” and play back music that was recorded in some portable form and installed in the piano. The best-known recording medium was a roll of paper that had holes corresponding to the notes that the piano would play. The idea of storing music as an abstract series of notes, to be played back by any compatible device, has come to be known as sequencing, which became an important chapter later on in the story of the synthesizer. It is interesting to note that this idea is much older even than the player piano. The music box “reads” a rotating cylinder that has protruding metal pins. Although the music box is not much older than the player piano, clocks had for quite some time been using similar mechanisms to sound the hours.

For the demanding classical composers and pianists, the piano could never have a “big” enough sound. A bigger sound means bigger strings and a bigger piano overall. A typical modern concert grand piano is nine feet long. Popular musicians, who discovered the piano in the 19th century, were not so demanding, at least in those days. From near the end of the 19th century until the early- to mid-20th century, popular ragtime and jazz were typically played on standard pianos. In the 1930’s, the Hammond Organ Company began producing an electric organ, targeted at churches, as a low-cost alternative to the pipe organ. But jazz musicians love to experiment, and before long they had discovered the new organ, bringing it back into the story of the piano after a hiatus of many centuries.

The Electro-mechanical Organ

The first Hammond organs were not so much electronic as electromechanical. They produced each tone using a tonewheel mechanism, in which a metal wheel (one for each key on the keyboard) spins in front of an electromagnetic pickup similar to a guitar pickup. Critics pointed out that this new instrument had a tendency to produce unexpected and undesirable sounds, primarily chromatic harmonics and key clicks. Chromatic harmonics resulted from the tonewheels and their pickups all being very close together. A given pickup would often detect the spinning of a tonewheel other than its own tonewheel, causing the organ to produce an extra note unrelated to the key being pressed. Key clicks were a simple result of the electrical connection inside the organ when the organist pressed a key. Pipe organ purists were disappointed, but to jazz musicians these artifacts made the electric organ “cool”. The original, tonewheel-oriented Hammond B3 organ, although no longer manufactured, is still recognized as a classic, even legendary instrument held in high regard by everyone who knows anything about music. Many modern electronic keyboards have a setting that simulates the original Hammond organs.

The Hammond organs brought another significant feature into the piano’s evolution: the drawbar. The drawbar was the electric organ’s answer to the pipe organ’s stop. The pipe organ’s stop allowed the organist to restrict airflow to selected sets of pipes. The electric organ’s drawbar allowed the organist to control the relative volume of the harmonics produced by the organ. The two mechanisms were very different, of course, and had a different kind of influence on the overall sound of the instrument, but they both represented a kind of rudimentary special effect that would whet the experimental appetites of musicians in the years to come.

The organ and all of its offspring for many decades afterward lacked the very feature that made the piano such a success: the intensity of the note varying with the intensity of the keystroke. However, this wasn’t a problem at all: the organist could control the overall intensity of the music with a foot pedal, and that was enough to make the electric organ a fixture on the popular music scene.

The Electric Organ

Hammond’s success attracted competitors, of course. Most of them dropped the tonewheel mechanism in favor of the vacuum tube. An organ based on vacuum tubes still had some moving parts involved in producing the sound, but it was considerably less mechanical and more electric than the tonewheel organs. Like the tonewheel mechanism, the vacuum tube contributed its own distinctive voice to the sound of the organ, surviving the critics’ complaints to become the stuff of legend. Also like the tonewheel, the vacuum tube has a devoted following, and there are many devices designed to make modern keyboards sound more like those based on vacuum tubes.

From the perspective of the average musician, vacuum tube instruments and everything descended from them are based on mysterious principles, but it’s not entirely rocket science. One of the basic principles of these electronic devices was already there in the tonewheel mechanism: the electromagnetic pickup. The pickup converts the tonewheel’s vibrations into an electrical signal. Other circuitry beyond the pickup may manipulate the electrical signal in some way, and then finally pass the signal to the speakers, which, of course, convert the signal into sound. Although technology advances have caused many of the details to change over the years, this fundamental means of using electricity to produce sound has remained the same over the years.

Side Trips

In 1946, Harold Rhodes introduced an interesting side branch to the evolutionary tree of the piano. The Rhodes Pre-piano was a different sort of instrument altogether, more like an electrically assisted glockenspiel than a piano. Its resemblance to a piano was only superficial, in that it had a keyboard. When the pianist strikes a key, a hammer inside the instrument strikes two metal bars and sets them vibrating. The vibration is detected by an electromagnetic pickup, similar to the pickups used in the Hammond’s tonewheel mechanism. The Rhodes, which ultimately became the Fender Rhodes, is unique. It did not develop into new kinds of pianos, but instead became yet another classic, leading to myriads of modern synthesizer specialists attempting to duplicate its distinctive sound. In fact, decades later, Yamaha introduced a synthesizer, the Yamaha DX7, that had a mode that attempted to duplicate the original Fender Rhodes sound. Of course the duplication was imperfect, but the sound produced by the DX7 went on to become famous in its own right, especially during the 1980’s.

The Wurlitzer Company introduced a close relative of the Rhodes in 1955, the Wurlitzer “electronic piano”. This instrument was not a piano, and not really electronic. From a layman’s point of view, the internal mechanism was not very different from the Rhodes: hammers would strike metal bars and cause them to vibrate, and the vibration would be converted into an electrical signal. However, the mechanisms were different enough that the Wurlitzer piano had a characteristic sound that was very different from the Rhodes, and that is what matters to those musicians who form the Wurlitzer’s large, still-present following.

The First Synthesizer

In 1947, engineers at Bell Labs created the world’s first transistor. Transistors could be arranged in groupings that would replace vacuum tubes and all of the associated electromechanical parts in an organ, using a fraction of the space, consuming far less electricity (though few cared in those days), and generating considerably less heat. As mentioned before, the basic principle of sound production did not change when instrument manufacturers switched from tube-based sound to transistor-based sound: the sound still originated in an electrical signal that could then be modified in some way before it was sent to the speakers.

Using this principle of electricity-based sound, experimenters in the late 1950’s and early 1960’s began building sound synthesizers. These devices at first bore no resemblance at all to a piano. They tended to be boxes within boxes, surrounded by dials and wires. There was no keyboard. Quite a bit of technical knowledge and a deep understanding of audio principles were necessary even to use them. In order to produce a particular sound, the user would connect one or more of these boxes with cables, then adjust various properties of the boxes using dials and sliders. If one understood enough, one could cause the synthesizer to produce sounds very similar to a real piano. Before long, those in the know began experimenting with ways to produce sounds similar to other instruments, and then finally, to produce sounds that had never been heard before. In addition to being nearly impossible to use, the first synthesizers had a serious limitation as musical instruments. Astounding as it may seem to those of us who discovered music after the electronic age began, early synthesizers could produce only one note at a time, that is, they were monophonic. Surprisingly, these devices were used for creating music.

Sampling Sounds

At about the same time that electricity-based sound production was germinating, Harry Chamberlin invented the Chamberlin, which, through some shady, greed-oriented machinations that are typical in the music industry, evolved into the Mellotron. Instead of synthesizing a sound, Chamberlin recorded the desired sound onto audiotape so that it could be played back when the pianist struck a key. The instrument contained an actual audiotape playback mechanism under every single key. And of course, for each instrument that the musician might want to simulate, there was a bank of eight-second audiotapes, again, one tape for each key. The technique of recording a sample of the desired sound for use in later playback is known, unsurprisingly, as sampling. Although audiotape is no longer used in modern devices, the technique of sampling persists.

Synthesizer Advances

The Moog (rhymes with vogue) Company, in 1970, took a decisive first step toward making synthesizers more accessible to musicians by introducing the Minimoog. The “advanced feature” of this instrument was the piano-style keyboard. Still, this was a monophonic synthesizer, capable of producing only one note at a time. It could not play even a simple chord, in spite of the apparent promise of the keyboard.

It took a few years for synthesizer manufacturers to begin making polyphonic instruments, that is, synthesizers capable of producing more than one note at a time. Moog took a step forward in 1975 with the Polymoog, but this was actually paraphonic, not a genuinely polyphonic instrument. It could play more than one note at a time, but there was a catch. If the pianist struck multiple keys simultaneously, all was well. But if the pianist struck and held one key and then later struck a second key, there was something strange about the sound. The second key’s sound would take on the characteristics of the first key’s sustained output. In other words, the instrument would not produce the initial sound that one would expect when striking the second key. It would simply sound as though it had already been struck. Perhaps a bit of an esoteric point, but musicians notice that sort of thing.

The Korg Company finally managed a truly polyphonic synthesizer in 1977, the PS-3200, which was able to produce sound independently and simultaneously for each of its 48 keys. Another huge benefit of the PS-3200 was the patch memory. Up until this time, the musician had to stop everything and painstakingly configure the instrument to produce the desired sound. This was not easy to do in the middle of a performance. The patch memory enabled the instrument to remember up to 16 configurations that could be recalled with the touch of a single button. Not long afterward, The Sequential Circuits Company introduced the Prophet-5, which in addition to being polyphonic and having patch memory, was the first synthesizer to be controlled internally by a microprocessor. The era of the analog synthesizer was coming to an end.

The Leap to Digital Technology

Up until this time, all synthesizers, and for that matter all electrical musical instruments, were analog devices. An analog device is a device that is controlled by changing the amount of electricity, that is, the voltage level, passing into it. A very simple example is a volume control. An analog volume control is typically attached to a knob or a slider. In turning the knob or moving the slider, the user is actually changing the amount of electricity that is passing through the volume control circuit. Thus the volume is a direct result of the actual voltage level. Early synthesizers’ control panels were covered with knobs and sliders. Adjusting any of these resulted in a change in the voltage level passing through that part of the circuit, which had a direct effect on the sound that the synthesizer produced. The advent of the microchip introduced a new means of manipulating synthesizer output, known as digital signal processing.

It’s not as terrifying as it may sound. There is no need for an advanced engineering degree to have a general understanding. An analog circuit sees the world in terms of voltage levels: a certain level goes into the circuit, the circuit does something internally, and a resulting voltage level comes out of the circuit. A digital circuit sees the world as pulses of electricity, and uses combinations of such pulses to represent numbers. Some pulses go into the circuit, the circuit perceives a number, performs some sort of math on the number, and sends the number back out as a new series of pulses.

Benefits of Digital Technology

The Kurzweil 250, introduced in 1984, was one of the earliest successful digital synthesizers. Why the switch to digital? One huge benefit of digital synthesizers, especially for starving musicians, is that they are much cheaper than analog synthesizers. They are also much smaller, because the electronics are all packed into microchips, which keep shrinking every year. Performing musicians especially appreciate the fact that their digital synthesizer sounds the same at the beginning of the performance as it does at the end of the performance, because the circuitry is not affected by temperature. Analog circuits change as they become warmer, which has an effect on voltage levels, and because the circuits see the world in terms of voltage levels, the temperature ultimately affects the sound.

There are some larger benefits of the transition from analog to digital technology. One of the benefits relates to sampling, which can now happen without the need for audiotape players under every key on the keyboard. Instead, a sample of the desired sound is stored digitally (as a series of numbers) in a chip inside the instrument. This technology gives the musician flexibility that was undreamed of before. Some of the chips in a modern synthesizer are fixed, unchangeable. The samples recorded in them are there to stay. But some modern synthesizers, such as the Yamaha PSR9000, also contain other chips that allow for changes. Thus the musician can download a sample (most instruments have room for many samples) into the synthesizer, use it at will, then discard it (or keep it, if there is enough space left on the chip) and download another one. The PSR9000 even allows the musician to record new samples via a microphone input.

Another benefit of digital technology is that sequencing, once done with rotating cylinders or rolls of punched paper, can now be done using computer files, also known as MIDI files. This once again represents an enormous gain in flexibility. A composer can now use a simple software application on a personal computer to create and edit very complex works—even complete scores, because modern synthesizers can produce more than one instrument sound simultaneously. In spite of all of this technology, the player piano lives on in the Yamaha Disklavier, which plays MIDI files from a standard compact disc.

The Present and the Past in the Future

Home computer processors are now fast enough to run software that duplicates the behavior of dedicated circuits in synthesizers. With this software running, a pianist can connect a MIDI controller keyboard to the computer and enjoy many of the benefits of a dedicated synthesizer.

Where will the future take the synthesizer? Frequently, into the past. As mentioned before, many very old instruments produced highly prized sounds that musicians strive to reproduce using modern technology: the Mellotron, the Fender Rhodes, even the analog circuit itself, as in the KORG microKORG, which contains circuitry that simulates analog characteristics.

The piano-style synthesizer has taken its place alongside the traditional piano as a mainstay of popular music. Surely, as long as we continue to make music, some of us will still make it with the synthesizer.


Duane Shinn has experimented with many different keyboards over the years, from the Moog down to his present keyboard, the Yamaha Digital Grand.

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